桉树对矿区污染土壤中Cu和Cd的耐受机制  

Tolerance Mechanisms of Cu and Cd by Eucalyptus in Mine Contaminated Soil

作　　者：韦月越 蒙敏[1] 黄雪芬[1] 龙海洋[1] 应成璋 王维生[1] 

机构地区：[1]广西大学环境学院,南宁530004

出　　处：《基因组学与应用生物学》2016年第1期227-234,共8页Genomics and Applied Biology

基　　金：国家自然科学基金项目(41263007);广西自然科学基金项目(2012GXNSFDA053023)共同资助

摘　　要：为明确桉树对土壤中Cu和Cd的耐受机制,采用某矿区实际污染土壤进行盆栽实验,研究了桉树对Cu和Cd的吸收和累积,分析了桉树根、茎和叶中Cu和Cd的亚细胞分布。实验结果表明,随土壤污染程度的增加,重金属的转运系数降低,Cu和Cd滞留在桉树根部。重度污染土壤中,桉树根部的Cu和Cd分别占植株总量的43%和90%。随污染程度的增加,桉树根部Cu和Cd的含量先增加后稳定,重度污染土壤中,桉树根部Cu和Cd的累积系数降低,对Cu和Cd的吸收受到限制。桉树吸收的Cu和Cd主要分布在根、茎和叶的细胞壁组分(>45%),随土壤污染程度的增加该比例大致保持稳定。重度污染土壤中,Cu和Cd在桉树根部可溶组分中的比例增加。综上所述,根部的滞留作用、根部的吸收限制、细胞壁固持作用及可溶组分的区隔化作用,是桉树耐受污染土壤中Cu和Cd的主要机制。In order to determine the tolerance mechanisms of Eucalyptus for Cu and Cd in soil, the actual mine contaminated soils for pot experiments were adopted, the absorption and accumulation of Cu and Cd by Eucalyptus were studied, and the subcellular distribution of Cu and Cd in Eucalyptus root, stem and leaf were also analyzed. The results showed that the translocation factors for heavy metals decreased with the increasing pollution levels in soil, Cu and Cd were detained in Eucalyptus root. In serious polluted soils, Cu and Cd in Eucalyptus root were account for 43% and 90% of its amount in plant respectively. With the increasing pollution levels, the contents of Cu and Cd in Eucalyptus roots increased firstly and then became stable. In serious polluted soils, the accumulation coefficients for Cu and Cd in Eucalyptus roots decreased, and the absorption for Cu and Cd was limited. Cu and Cd absorbed by Eucalyptus were mainly distributed in the cell wall fractions （〉45%） in root, stem and leaf, the proportions remained relatively stable with the increasing pollution levels in soils. In serious polluted soils, the proportions of Cu and Cd in the soluble fraction in Eucalyptus roots increased. In conclusion, retention in root, absorption limit in root, binding to cell wall and soluble fraction compartmentalization were the main tolerance mechanisms for Cu and Cd in Eucalyptus at contaminated soil.

关 键 词：亚细胞分布 桉树 铜 镉 耐受机制 

分 类 号：S792.39[农业科学—林木遗传育种] X53[农业科学—林学] X173[环境科学与工程—环境工程]